Question

我想动态地在另一个片段中添加一个片段。外部片段是 DialogFragment ：

public class MapFragmentDialog extends DialogFragment implements OnMapClickListener, OnMapLongClickListener,
    OnMarkerDragListener {

FragmentManager fmanager;
Fragment fragment;
SupportMapFragment supportmapfragment;

public static MapFragmentDialog newInstance() {
    MapFragmentDialog f = new MapFragmentDialog();
    return f;
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

    super.onCreateView(inflater, container, savedInstanceState);

    View v = inflater.inflate(R.layout.map_fragment, container, false);

    // *********** add myMapFragment

    FragmentManager fragmentManager = getActivity().getSupportFragmentManager();
    FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();

    // add a fragment
    MyMapFragment myFragment = new MyMapFragment();
    fragmentTransaction.add(R.id.myfragment, myFragment);
    fragmentTransaction.commit();
    myMap = ((SupportMapFragment)getActivity().getSupportFragmentManager().findFragmentById(R.id.myMap)).getMap();

    return v;
}

map_fragment 布局如下：

<TextView
    android:id="@+id/txtHelp"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:gravity="center_vertical"
    android:paddingBottom="6dip"
    android:textAlignment="center"
    android:textAppearance="?android:attr/textAppearanceSmall"
    android:textSize="12sp" />
<FrameLayout
    android:id="@+id/myfragment"
    android:layout_width="0px"
    android:layout_height="wrap_content" />

我的内部片段 MyMapFragment ：

public class MyMapFragment extends Fragment {

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View myFragmentView = inflater.inflate(R.layout.my_map_fragment, container, false);
    return myFragmentView;
}}

my_map_fragment 布局包含：

<fragment
    android:id="@+id/myMap"
    android:layout_width="match_parent"
    android:layout_height="300dp"
    class="com.google.android.gms.maps.SupportMapFragment" />

我在DialogFragment上获取地图片段时遇到异常，此行有NullPointerException

myMap = ((SupportMapFragment)getActivity().getSupportFragmentManager().findFragmentById(R.id.myMap)).getMap();

Answer 1

我记得看到片段中的片段只是动态地工作而不是放置XML。我认为Abd El-Rahman El-Tama有正确的想法使用frameLayout而不是直接指定片段

Answer 2

动态更改Fragments所需的全部内容

1） FrameLayout中的Layout如下：

<FrameLayout
android:id="@+id/fragment"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />

2）将FrameLayout初始化为activity，如下所示： -

FrameLayout fragment = (FrameLayout) findViewById(R.id.fragment);

3）启动Fragment事务如下：

getSupportFragmentManager().beginTransaction().replace(R.id.fragment, new MyFragment()).commit();

或者

FragmentManager fragMan = new FragmentManager();
fragMan.beginTransaction ();
fragMan.replace (R.id.fragment);
fragMan.commit ();

动态地在另一个片段内添加片段

2 个答案: